The end is nigh ... for HOT ROD's Win Your Dream Engine Contest. It all began back in June '03. Sponsored by Edelbrock, Comp Cams, Performance Distributors, Speed-Pro, Milodon, and ARP, the idea was that readers would design an engine using any parts they wanted from the sponsors' catalogs. We've already covered the Ford (Dec. '04), the Pontiac (Jan. '05), and the Mopar (Oct. '05). At long, long last, it's time for Steve Hammonds' Chevrolet.
Out of 6,039 entrees, Steve caught our attention with a strictly old-school plan to duplicate his high-school sweetheart (his other sweetheart, he married the primary one): A high-revvin,' manual-trans, drop-the-clutch-at-6,000-rpm, bang-the-gears, small-journal 302-based engine, built using an early 327 4-inch-bore block and 283 3-inch-stroke crank. At 0.030-over, that yields 306 ci. As Steve puts it, "This was the basic engine in my '57 Chevy I had in 1973. It was replaced with a mild 350 and automatic trans to use as my daily driver. With a mortgage, car payments, a wife, and two kids, I don't have enough money to cure my insatiable appetite for cars and speed."
So we took pity on him. Besides, what's not to love about a screamin' 302? And more besides, he still has the original '57 waiting at home for reanimation. Anyway, it'll be easy: a Chevy just falls together, right? Not exactly.
Who would have thought we couldn't find a block? Apparently small-journal '62-'67 327s that clean up at 0.030-over don't grow on trees. Two locally obtained cores turned out to be rust-buckets. Local SoCal core-exchanges struck out. Then we discovered a huge nationwide core bank, A&A Midwest Enginequest, and the company answered our prayers with an engine so pristine it nearly cleaned up standard. Be aware that A&A doesn't sell directly to the general public, but you can contact it for general availability and then arrange to purchase the parts through your local machine-shop.
Dougan's assembled the engine per Steve's specs, just the way he would have done a no-holds-barred engine circa 1973: a classic dual-carb tunnel-ram, Comp Magnum mechanical cam, domed Speed-Pro forged pistons, and Edelbrock Victor Jr. heads. Well, maybe not the heads. The camel-hump era had nothing remotely close to high-flowing Victor Jr. heads (eat your heart out, Penske). But they did have cheap, high-octane fuel, and Steve will miss those 29-cent/gallon prices: Those big-E heads and the domed slugs produce a no-compromise 11.75:1 compression ratio, requiring 100-octane Rockett unleaded gas with 41 degrees of ignition advance.
Having flown in all the way from Woodstock, Georgia, Steve was sweating as Westech Performance made increasingly higher rpm runs in an effort to find the engine's power peak-which was finally nailed at 6,800 rpm, where it topped out at 409 hp. Heck, even the torque didn't ring the bell until 5,100, where 354 lb-ft was recorded by the SuperFlow dyno. But don't sneer at retro tech: The engine made 1.34 hp/ci, the highest ratio of any of the Dream Engines. And that also blows away the 360hp Trans Am 302s of the late '60s. Steve, get out those 4.56s!
Engine Builder's Specs
All dimensions in linear inches, except as noted.
Short-Block
Displacement: 306.1 ci
Bore: 4.030
Stroke: 3.00
Block deck height: Milled to 9.021
Piston deck height: 0.016 (below deck)
Piston volume: 17.9cc dome
Head gasket compressed volume: 8.9cc
Compression ratio: 11.75:1
Rod length: 5.7
Piston compression height: 1.805
Piston-to-wall clearance: 0.004
Main-bearing clearance (Nos. 1-4): 0.0029-0.0035
Main-bearing clearance (No. 5): 0.0026-0.0030
Rod-bearing clearance: 0.0026-0.0030
Rod side-clearance: 0.013-0.019
Crankshaft thrust clearance: 0.004
Piston-ring endgap: 0.020/0.018/0.026
Pressed piston pin-to-rod: 0.0008 minimum
Piston-to-head clearance: 0.055
Cylinder Heads
Valve size: 2.08/1.60
Combustion chamber volume: 64 cc
Port volume: 215/85 cc
Flow at 0.500 lift: 265/207 cfm @ 28 in H20
Flow at 0.600 lift: 281/217 cfm @ 28 in H20
Valvespring od/id: 1.509/0.697
Valvespring seat pressure: 135 lb @ 1.850
Valvespring open pressure: 325 lb @ 1.345
Valvespring coil-bind height: 1.100
Spark plugs: Autolite Racing AR3933, gapped at 0.035
Critical Fasteners
ARP head bolts: 60 lb-ft (Teflon sealant on threads, ARP lube under washer)
ARP main and oil-pump studs: Bottom hand-tight, back off 11/44-turn (oil)
ARP main stud nuts: 70 lb-ft (ARP lube)
ARP oil-pump stud nut: 60 lb-ft (oil)
ARP rod-bolt nuts: 40 lb-ft (ARP lube)
Pioneer balancer bolt: 75 lb-ft (oil)
Comp rocker-arm studs: 35 lb-ft (red Loctite)
Grade-8 cam bolt: 25 lb-ft (red Loctite)
ARP intake bolts: 30 lb-ft (RTV silicone)
Balance
Piston weight: 451.0 grams
Piston-pin weight: 130.0 grams
Ring weight: 48.0 grams
Rod-bearing weight: 44.0 grams
Bobweight: 1,641 grams
Camshaft
Type: Mechanical flat-tappet
Grind: Comp Cams Magnum 294S
Duration, advertised: 294/294 degrees
Duration, 0.050 tappet lift: 250/250 degrees
Lobe displacement angle: 110 degrees
Installed intake centerline: 105 degrees
Lobe lift: 0.356/0.356
Rocker arm ratio: 1.52:1
Valve lift at zero lash: 0.541/0.541
Valve lift at running lash: 0.519/0.519
Valve lash: 0.022/0.022 hot
Camshaft base circle: 1.150/1.150
Pushrod length: 7.900/7.900
Piston-to-valve clearance: 0.145/0.300
DREAM CHEVY 306 PARTS LIST DESCRIPTION PN SOURCE PRICE* LONG-BLOCK Core 327 small-journal bare block EN-C327BA A&A Midwest $350.00 Core 283 forged-steel crank N/A Castillo's $125.00 Core 2.00-inch journal rods (8 required) N/A Dougan's $80.00 Speed-Pro forged pistons with pins (8 required) L2210AF-30 Summit Racing $411.12 Speed-Pro file-fit piston rings R-9342-035 Summit Racing $96.95 Speed-Pro Competition Series rod bearings 8-7065CH-10 Summit Racing $62.69 Speed-Pro Competition Series main bearings 138M-10 Summit Racing $55.99 Speed-Pro Competition Series cam bearings 2100M Summit Racing $35.69 Pioneer 6.72-inch-od SFI harmonic damper 872022 Summit Racing $149.39 Edelbrock head with valves (2 required) 77579 Summit Racing $1,139.00
INDUCTION & FUEL Edelbrock Street Tunnel Ram intake, complete 7110 Summit Racing $259.95 Edelbrock Performer 500-cfm carb (2 required) 1404 Summit Racing $449.76 Edelbrock throttle linkage kit 7097 Summit Racing $26.95 Edelbrock calibration kit (2 required) 1486 Summit Racing $47.88
OILING Milodon oil pan, LH dipstick 30900 Summit Racing $139.88 Milodon oil pickup 18314 Summit Racing $34.88 Speed-Pro high-volume oil pump 224-4143 Summit Racing $26.95 Speed-Pro heavy-duty pump shaft 224-6146E Summit Racing $10.99 Silver Seal dipstick and tube TW6505CP Dougan's $7.00 Used stock bypass valve N/A Wrecking yard $10.00 Mr. Gasket spin-on oil-filter adapter 1270 Summit Racing $9.75GASKETS Fel-Pro head gasket (2 required) 1010 Summit Racing $73.90 Fel-Pro intake set 1206 Summit Racing $14.88 Fel-Pro RACE set 2702 Summit Racing $18.95 Fel-Pro one-piece oil-pan gasket, LH dipstick 1880 Dougan's $36.00 Fel-Pro Cork-Lam valve-cover set 1604 Summit Racing $27.95
HARDWARE ARP main studs, small-journal, no windage tray 134-5402 Summit Racing $39.75 ARP head bolts, with stainless steel outer row 134-3603 Summit Racing $96.99 ARP Wave-Loc 11¼32-inch rod bolts 134-6401 Summit Racing $59.88 ARP oil pump mounting stud 230-7004 Summit Racing $6.50 ARP timing-cover bolts {{{200}}}-1501 Summit Racing $9.95 ARP intake bolts 134-2001 Summit Racing $12.88 ARP valve-cover studs 400-7603 Summit Racing $18.88 Pioneer harmonic-damper bolt 859012 Dougan's $6.00 Pioneer oil-pan bolts 854001 Dougan's $15.00 Moroso distributor holddown clamp 26200 Summit Racing $7.95
IGNITION Performance Distributors distributor & coil 14720 Performance Dist. $295.00 Performance Distributors Live Wires C9053 Performance Dist. $95.00 DYNO CONSUMABLES Fram Autolite racing spark plugs (8 required) AR3933 Summit Racing $37.52 Lucas 10W30 synthetic engine oil (7 quarts) 10050 Summit Racing $48.65 ACDelco oil filter PF1218 Rock Auto $4.83
ACCESSORIES Edelbrock Elite tall aluminum valve covers 4249 Summit Racing $71.95 Pioneer freeze plugs PE100BR Summit Racing $10.99 OEM Paints {{{Chevrolet}}} Orange/Red engine paint OE62020 The Paddock $26.95 Pioneer fuel pump block-off 839033 Dougan's $6.00 Used stock timing cover N/A Dougan's (Free) Silver Seal timing tab 6544R Dougan's $5.00
MACHINE WORK & OTHER LABOR 283 crank: magnetic-particle-inspect, grind
0.010/0.010, heat-treat N/A Castillo's $327.00 Clean and inspect parts, deburr block, install freeze plugs and cam bearings, machine block, fit pistons and pins, resize rods, balance assembly, surface heads, valve job, assemble engine. N/A Dougan's $2,667.00 TOTAL $8,467.72
*All prices are as of press-time and are subject to change.
PROVEN POWER RPM LB-FT HP RPM LB-FT HP 3,000 305 174 5,{{{100}}} 354 343 3,100 302 178 5,{{{200}}} 352 349 3,200 301 183 5,{{{300}}} 351 354 3,300 301 189 5,400 351 361 3,400 302 195 5,500 350 367 3,500 306 204 5,{{{600}}} 351 375 3,600 311 213 5,700 350 380 3,700 315 222 5,800 347 383 3,800 318 230 5,{{{900}}} 343 385 3,900 321 238 6,000 339 387 4,000 325 247 6,100 335 390 4,100 328 256 6,200 334 395 4,200 333 266 6,300 332 398 4,300 336 275 6,400 328 400 4,400 340 285 6,500 326 403 4,500 344 295 6,600 322 {{{405}}} 4,600 348 305 6,700 320 408 4,700 351 314 6,800 316 409 4,800 352 322 6,900 310 407 4,900 352 328 7,000 302 403 5,000 353 336 HRM
